Can You Solve The Chameleon Riddle?

A museum has 13 blue, 15 red, and 17 green chameleons. Whenever two chameleons of different colors meet, they both change into the color of the other chameleon (if blue and red met, for example, they would both turn green). As the chameleons mingle, is it ever possible that they …

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TED-Ed’s Frog Riddle Is Wrong

TED-Ed presented a riddle last week based on a classic probability problem. However in the riddle there is a small and seemingly insignificant detail that changes the calculation. In this video I present the pertinent details of the frog riddle, explain its connection to the boy or girl paradox, and …

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Check your intuition: The birthday problem – David Knuffke

View full lesson: http://ed.ted.com/lessons/check-your-intuition-the-birthday-problem-david-knuffke Imagine a group of people. How big do you think the group would have to be before there’s more than a 50% chance that two people in the group have the same birthday? The answer is … probably lower than you think. David Knuffke explains how …

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Can you solve the airplane riddle? – Judd A. Schorr

View full lesson: http://ed.ted.com/lessons/can-you-solve-the-airplane-riddle-judd-a-schorr Professor Fukanō, the famous scientist, has embarked on a new challenge – piloting around the world in a plane of his own design. There’s just one problem: there’s not enough fuel to complete the journey. Luckily, there are two other planes to help. Can you help …

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Can you solve the counterfeit coin riddle? – Jennifer Lu

View full lesson: http://ed.ted.com/lessons/can-you-solve-the-counterfeit-coin-riddle-jennifer-lu You’re the realm’s greatest mathematician, but ever since you criticized the Emperor’s tax laws, you’ve been locked in the dungeon. Luckily for you, one of the Emperor’s governors has been convicted of paying his taxes with a counterfeit coin, which has made its way into the …

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Can you solve the control room riddle? – Dennis Shasha

View full lesson: http://ed.ted.com/lessons/can-you-solve-the-control-room-riddle-dennis-shasha As your country’s top spy, you must infiltrate the headquarters of the evil syndicate, find the secret control panel, and deactivate their death ray. But your reconnaissance team is spotty, and you have only limited information about the control panel’s whereabouts. Can you solve the control …

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The Infinite Hotel Paradox – Jeff Dekofsky

View full lesson: http://ed.ted.com/lessons/the-infinite-hotel-paradox-jeff-dekofsky The Infinite Hotel, a thought experiment created by German mathematician David Hilbert, is a hotel with an infinite number of rooms. Easy to comprehend, right? Wrong. What if it’s completely booked but one person wants to check in? What about 40? Or an infinitely full bus …

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How do you decide where to go in a zombie apocalypse? – David Hunter

View full lesson: http://ed.ted.com/lessons/how-do-you-decide-where-to-go-in-a-zombie-apocalypse-david-hunter Can geography save your life in case of, say, a zombie apocalypse? Understanding the push and pull factors that create geographic movement — or how people, resources, and even ideas travel — might help you determine the location that’s best for survival. David Hunter playfully analyzes …

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